1. Field of the Invention
This invention relates to power supplies and more particularly relates to low-cost self-healing power supplies.
2. Description of the Related Art
A power supply, sometimes known as a power supply unit or PSU, is a device or system that supplies electrical or other types of energy to an output load or group of loads. A power supply, in some embodiments may be configured to convert power in one form to another form, such as converting AC power to DC power. The regulation of power supplies is typically done by incorporating circuitry to tightly control the output voltage and/or current of the power supply to a specific value. The specific value is closely maintained despite variations in the load presented to the power supply's output, or any reasonable voltage variation at the power supply's input.
For example, in an electronic device such as a computer, the power supply is typically designed to convert an AC voltage input such as is traditionally provided by a conventional wall socket, into several low-voltage DC power outputs for transmission to the internal components of the electronic device. Conversion is typically performed in stages that may include various different stages such as a rectification stage, a pre-regulation stage such as an active harmonic filter, a regulator/chopper stage, etc. The stages may be a boost stage, a buck stage, or other derivative topology.
Some stages in a power supply may include a pulse-width modulator that regulates a bus voltage by sensing a controlled bus voltage and adjusting a switching duty cycle to regulate the controlled bus signal to some target value. Conventional power supplies typically use a power Metal Oxide Semiconductor Field-Effect Transistor (“MOSFET”) as the switching component because power MOSFETs can switch at very high speeds. However, power MOSFETs are also one of the most likely components to fail in a power supply. When a power MOSFET in a conventional power supply fails, the power supply is no longer able to continue providing power, and therefore, systems powered by the power supply remain inoperational until the faulty power supply is replaced. This can result in a significant loss of productivity.
Artisans have attempted to resolve failure problems in power supplies by implementing completely redundant power supplies with a power back plane. However, the costs of implementing fully redundant power supplies can be expensive and inefficient. Thus, a need exists for a low cost self-healing power supply that provides fault protection at a lower cost than implementing fully redundant power supplies.